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buiten tstrs @anni @ffirs- FLAVIUS J. VAN VORHIS AND -'.lllOlllAS C. WORKMAN, STOCKWELJ,

` INDIANA.

Letters Patent N0. 76,676, dated April 14, 1868.

IMPROVBMENTIN ROTARY STEAM-ENGINES.

TO ALL WHOM IT MAY CONCERN l v Be it known that we, Fnnvrus J. VAN Volants and THOMAS C. WonKs'rAN, of Stockwell, in the county rof Tippecanoe, and State of Indiana., have invented new and useful Improvements in Rotary Steam-Engines; and we do hereby declare that the follo`wing is a full, clear, and exact description thereof. reference being had to the accompanying drawing, making part of this specification, in whieh- Figure 1 isa vertical longitudinal section at oneside of the piston.

Figure 2 is a `vertical transverse section through the centre of the engine.

Figure 3 is a horizontal plan view of the steam-chest. Y

Similar letters of reference indicatecorrespondmg parts in the several figures'.

To enable others skilled in the art tom'ake and use our invention, we will proceed to describe its construction and operation. v

A is the steam-case, which is here shown of rectangular form, in its external appearance, but which may be of any-,convenient or desirable form applicable to the construction of this engine. .The case is composed of three pieces of castings, a middle and two side-plates. The middle plate is of the thickness required for the transverse diameter of the piston, and is pierced with an opening ofthe size required for the piston. The steam and exhaust-passages E and F are also formed in the sides of this plate, as shown in iig. 1, land so also is the seat ofthe reversing-valve e, in its top edge. This plate has iianges cast on' its ends to receive the side-plates.

The object of this construction of the steam-case is to make it simple to mould and east, and so that it maybe conveniently and cheaply tted together. The side-plates of the case have grooves to receive the outer edges of the valves D, and serve asguides for them.

The pistorfB may be cast either solid or in three pieces, to be bolted. together, as may be foundy most convenient in fitting it up. The middle portion of the piston is made to t steam-tight in the steam-chamber, and serves asa partition, separating it into twb compartments, forming a double-acting engine. The side-plates or portions of the piston are as much less in diameter than the middle portion as may be required for the steam-- space, or rather as may be required for piston-surface, which latter is obtained by extending a portion of the side-plates out to the perimeter ofthe middle plate, forming the piston proper, against which the steam ac ts, as shown at B. -These are arranged opposite each other, as indicated bythe dotted lines on the piston in fig. 1. The object being to make the engine doubleaeting, there are also two valves, D, and a double system of steam-x passages to correspond with the double ste'am-chambers and pistons, all constructed alike, except that the pistons B and cam-rings C, that actuate the valves D, are arranged opposite each other, so as to operate alternately, so that while the steam is cut oi one piston, it is admitted under full-head upon the other. v

D are valves, that servethe double purpose of admitting steam to and cutting it oii the pistons alternately,

vand also as abutments to the back pressure of the steam, a shoulder near their lower ends, resting upon the perimeter of the side-plate of the piston, forming the abutment. These valves are actuated by means of the projecting points or pins d, and by the cam-groove C, in the sides of the pis-ton. Cavities, I, are formed in the cap-piece A. of the steam-chest, to receive the upper lends of the valves, and in which they wor-k steam-tight. The valves are pierced through, near their upper ends, as shown at S, figs. 1 and 2', and by dotted lines in fig. 3, for the passage of the steam, as hereafter described, and, also, in connectipn with thecavities l, in cap-piece A, as a means of balancing thevalves, or relicving'them of' the downward pressure ofthe steam. The upper end of the valve working -steam-tight in the cavities I, prevents the steam from. getting above them, and the t prcssureof the steam against the surface of the valve above the openings S being equal to that below, there c a be no pressure upon the valve prepon'derating in any direction.

The steam is admitted by port G, in the cap-piece A", and passes down the passages z' z' z', and through the.

openings S, in the valves D, thence along the passages H, down theplas'sages E, into the steam-space between the pistons B and the lower ends of the valves D, which form the abutments for the back pressure o f the steam.

tiall;r as set forth.

The pressure ofthe steam upon the piston B drives it around' imtil it passies `the exhaust-port F, through which it escapes to the open air. Atthis point the cam-groove C raises the valve D, untilV the openings S nre closed l by being housed in the cavities I, in the cap-piece A, which cuts oif the further admission of steam on that side of the steam-chamber, untilthe piston B has revolved beyond tliesteam-induction -port E.

The reversing-valve e, fig. 1', and indicated in red dotted lines, fig. 3, is used only in giving direction to the rotation of the piston, being applicable to such enginesV as require reversing, such as locomotives arid steamboatengnes. In stationary engines, when the rotation is always invone direction, this valve, and also one of the induction-ports, with the corresponding exhaustfport', may be omittei. I i

It will be observed that the exhaust-port behind the piston sgalways open for the free escape ofthe steam, hen-ce there is no back pressure.

Having thus fully described our` invention, what we claim as new, and. desire to secure by Letters Patent, is i f Y' 1. The construction of the caso A, substantially as set forth. t

2. Theconstruction and arrangement of the piston B anni valves D, substantially as set fortli.-

3. TheA arrangement of the vvalves D, with the piston B and cam-grooves` C, substantially as set forth.J

4. The arrangement of the steam-passagesz'z'z', with the valves D, and `the cavities I, substantially as set; forth. Y l y y 5. The arrangement of the valves D, with the passages H and ports E, substantially as set forth.

6. The arrangement of the reversing-valve e, the'steam-induction ports E, and exhaust-ports F, substan FLAVIUS J. VAN vonnis, THOMAS e. WORKMAN.

Witnesses: v O. F. MAYIIEW, D. S. FimeUsoN. 

